High Density Polyethylene, sometimes known as HDPE, is one of the most widely used thermoplastic materials on the market right now. This incredibly adaptable polymer, which has a very high strength to density ratio, is used to make plastic containers, carrier bags, wire insulation, toys, kitchenware, home items, and more.

High DPE cannot be glued since it is resistant to a wide range of solvents. Welding is required to create pipe junctions. The moulding technique used to create a particular sample can affect the physical properties of HDPE; to some extent, this is influenced by the globally standardised testing procedures used to determine these parameters for a particular process. For instance, rotational moulding uses the notched constant tensile load test (NCTL) to gauge a sample's susceptibility to environmental stress cracking.

The most popular plastic, polyethylene, which makes up over 34% of the global plastic market, is a kind of HDPE. It is a polymer comprised of a sizable number of repeating units (sometimes referred to as monomers), and its usual chemical formula is (C2H4)n. High density polyethylene has relatively little branching (when compared to other categories of polyethylene). Below is an illustration of the general HDPE structure.